Core for forming screw-threads on castings



2 Sheets-Sheet 1.

G; OOWING.

GOREPOR FORMING SCREW THREADS 0 GASTINGS Patented Nov. 29

INVENTOR.

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2 Sheets-Sheet 2.

G. GOWING. 001m FOR FORMING SCREW THREADS ON GASTINGS. No. 250,206.

INVENTOR Patented Nov. 29,1881.

NESSES E ATTORN YS N. PETERS, Plmlo-Llllwgmpher. Washington, D. c.

"tion to T and joints.

UNITED STATES PATENT OFFICE.

GEORGE OOWING, OF CLEVELAND, OHIO.

CORE FOR FORMING SCREW-THREADS ON OASTINGS.

SPECIFICATION forming part of Letters Patent No. 250,206, dated November 29, 1881,

Application filed January 16, 1878.

To all whom it may concern Be it known that I, GEORGE OOWING, of Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Cores for Forming Seamless Screw-Threads on Castings; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being bad to theaccompanying drawings,which form part of this specification.

My invention relates to a new and useful improvement in cores for forming a seamless screw-thread on the interior ot'castings-suoh, for instance, as the joints used in pipe-couplings for gas, water, and steam pipes, the bases and reverse couplings, &c., in steam-radiators, and in other like places wherever a screwthread is to be formed on the interior of a casting in the operation of molding.

In the drawings, Figure 1 is a view in elevation of a core embodying my invention. Fig. 2 is a view of the same in longitudinal central section. Fig. 3 is a separateview of the core-arbor. Fig. 4 presents avariation in which the central or core arbor is dispensed with. Fig. 5 presents another variation in which there is a core-arbor, but not projecting at either end beyond the body of the core and core-print proper. Fig. 6 shows the application of the invention in the formation of the core for a straight pipe-joint; Fig. 7, its adapta- Fig. 8 shows its application in making the cores for return joints or couplings.

The object of my invention is to produce a core whereby hydraulic, steam, or other fittings maybe produced with afemale thread perfectly cast upon them, and not requiring that said threads shall be subsequently cut or dressed; and it consists in the construction and combination of parts, as hereinafter described.

A is the core-print; B, the screw-threaded core, which is formed in continuation of the core-print A, that portion which forms the entrance to the screw being adjacent to the coreprint. This insures ample protection to the end of the screw-thread which is eventually to form the entrance of the screw, so that the casting will not need to be subsequently dressed at this point in order to be ready for use.

0 is the core-arbor. It may or may not be employed; but, if employed, it may or may not be hollow, andmay or may not be ventilated. I prefer, however, that it be a hollow ventilated arbor, for the ready escape of vapor or gases that may be set free in the operation of casting.

C and G are the projecting ends of the corearbor 0. It is not essential that the ends should thus project; but it is preferable, in order that they may serve the purposes of dowels for readily securing the core to other parts, 1), of a core, or to the adjacent walls of the mold, or to the flask. A core of this form and construction is superior in that its enteringthread is sure to be perfect, owing to the protection afforded by the adjacent core-print. Moreover, it is convenient, as it affords a ready screw-thread attachment to the plain portions of the core. Thus, if it is desired to make a core for a straight joint screw-threaded on its interior at both ends, like an ordinary cast-pipe coupling, it is only necessary to take a plain core, D, of the required length and to attach these screw-cores at each end, as shown in Fig. 6, wherein the dowel ends 0 enter corresponding holes in the end of the central or plain portion of the core; or, as shown in Figs. 7 and 8, it is equally well adapted for attachment to cores for any kind of screw-connectionas, for instance, the different kinds of pipe-joints used in gas, water, and steam fittings, for the bases of steam radiators, and in various like localities.

The arbor is provided with wings c, to give it a firmer seat within the core and core-print.

The core and core-print are formed of sand.

or other refractory substance of the nature usually employed in making cores, and may be baked, if necessary, in order to harden them.

It will be understood that in using the phrase seamless core 1. mean a core formed Without the fin or rib that is caused by the sections of a core-box, and which require dressing off.

What I claim is- 1. The combination of two or more seamless screw-cores having male threads and ventilatin g core-arbors, which project and form dowels,

5 with a tubular ventilating core-arbor, the end Witnesses:

with a main ventilated core having dowel-sock- In testimony whereofl hztve signed my name ets, substantially as and for the purposes set to this specification in the presence of two subforth. scribing witnesses.

2. The seamless screw-core in combination GEORGE OOWING.

of which projects and serves as a dowel, sub- F. TOUMEY,

stantially as and for the purpose set forth. WILLIAM E. DONNELLY. 

